There are four LEDs on the left side of the board. From top to bottom,
they are:

POWER: Board-level power indicator, just about the USB connector.

RX: Serial data receive LED.

TX: Serial data transmit LED.

CHIP: General-purpose board LED.

The POWER LED will light up when the KBPM is connected to any power source.
The CHIP LED will flash and decay on a 5-second cycle when the Kegboard
firmware is listening, and on a 1.25-second cycle when the Kegboard
firmware has recognized connection to a compatible Android tablet.
The RX and TX LEDs will rapidly flash when the flow meter is reporting
pulses or ticks.